This invention relates to supports, particularly supports for identification plates suitable for use on vehicles, and to signs e.g. identification devices, such as identification plates suitable for use on vehicles.
It is known that numberplates for motor vehicles are stolen. This may be done to. ‘clone’ a car for use in the pursuit of crime or to avoid paying city congestion charges, for example.
Accordingly, it is desired to provide means such as a support usable with an identification device, for example a vehicle numberplate, which has measures to prevent its theft and/or which is readily identified or identifiable as having been stolen.
Moreover, it is desirable to be able to identify the nature and/or provenance of an article remotely.
In the field of motor vehicle licence plates, solutions have been proposed which enable a person to remotely obtain information concerning the vehicle to which the plate is attached and/or other information pertaining to the driver (e.g. insurance details) and so on.
These passive tags comprise a microwave antenna which is necessarily large to receive an interrogation signal and to receive enough power to activate the circuitry. The large antenna ensures that it may be impossible or at least difficult to form/emboss such a plate.
U.S. Pat. No. 5,621,571 discloses an integrated retro-reflective electronic display comprising a substrate, a ground plane, a dielectric substrate, an antenna network comprising a pair of micro switch patch antennas, and a retro-reflective layer which bears indicia. Conventional retro-reflective layers incorporate a metal layer to retro-reflect light. In this patent, the retro-reflective layer incorporates a disparate metal layer which has enough ‘free space’ to allow the passage of radio frequency signals (at 915 MHz). Other retro-reflective materials which do not comprise a metal layer are also disclosed. The antenna network is fed via a coaxial connector mounted at the rear of the display through which the network may be connected to any outboard electronic module (for example a power source, memory device, power source and so on).
It is also desired to provide solutions to the theft and/or unwanted removal problem which can ensure that any sign so-removed is unusable thereafter.
In our previously filed International (PCT) patent application PCT/GB02/02773 (published as WO 02/102626 A1) we disclose and claim an identification plate comprising a supporting substrate having a retro-reflective major surface and a transparent sheet material having indicia printed thereon, the transparent sheet material being adhered to the retro-reflective major surface such that the indicia are located in contact with, or at least adjacent to, the retro-reflective major surface, and wherein one or more lines of weakness may be formed in the substrate.
The plate is to be adhered to a surface (for example a body of a car) using sticky pads which would be located either side of the or each line of weakness. If a thief or vandal attempts to remove the plate from the surface to which it is adhered, the plate will snap about the line of weakness. The snapping of the plate causes the transparent sheet to become stretched and/or delaminated from the substrate which makes the plate unsightly and provides an obvious visual indication that the plate has been removed from a surface.
It is an object of the present invention to provide a support which increases the security afforded to identification plates, in particular, although not exclusively for use with signs, e.g. identification plates, provided with lines or areas of weakness.
It is a further object of the invention to provide signs which comprise tamper evident means to indicate, for example, unauthorised or unwanted removal.